Undifferentiated large cell carcinoma is a rare subtype, highly malignant and aggressive form of undifferentiated carcinoma which occurs more frequently in parotid. In this report, we describe the clinical and 19 García PE y col. Carcinoma indiferenciado tipo células grandes www.revistapatologia.com Patología Revista Latinoamericana Correspondence Rodolfo Esteban Ávila firstname.lastname@example.org histological features of an undifferentiated large cell carcinoma, its proliferative potential and we performed the differential diagnosis with other salivary neoplasms. A 67-year-old male patient who consulted for a hard nodule of right parotid of 6 months of evolution, with signs of facial paralysis. Ultrasound was performed and the tumor was excised. The biopsy was studied with H/E and immunolabeling was performed with Ki67 to analyze their proliferative capacity. The tumor, non-encapsulated, was formed by large cells, greater than 30 µm, with large nuclei. In areas appeared eosinophilic spindle, anaplastic and giant multinucleate cells dispersed among the other cell types. Mitotic figures, vascular invasion, necrosis and hemorrhage were observed. Ki 67 expression was strongly positive. The microscopic diagnosis corresponds to an undifferentiated large cell carcinoma, with positive proliferative potential. Its diagnosis is histopathological since the clinic does not differentiate it from other salivary tumors. In their differential diagnosis, we included undifferentiated or poorly differentiated metastatic carcinomas, anaplastic and large cell lymphomas and melanoma.